University of
California, Davis
Physics Department
Condensed Matter Seminar
**********************************
Dr. Choong-Shik Yoo
Lawrence Livermore National
Laboratory
"High Pressure Materials Research at the APS"
Application
of high pressure significantly alters the interatomic distance and thus
the
nature of intermolecular interaction, chemical bonding, molecular
configuration, crystal structure,
electronic structure, and stability of solid. With modern advances in
high-pressure technologies, it is feasible to achieve a large (often up
to a
several-fold) compression of lattice, at which condition material can
readily
transform into a new physical and chemical configuration. The
high-pressure
thus offers enhanced opportunities to discover new phases, both stable
and
metastable ones, and to tune exotic properties in a wide-range of
atomistic
length scale, substantially greater than those achieved by other
thermal and
chemical means. Futhermore, combining
modern laser and synchrotron x-ray technologies the high-pressure truly
becomes
a powerful tool in materials research.
In this talk, I will describe new opportunities at the
third-generation
synchrotron APS for high-pressure materials research and discuss about
a few
examples of phase transformations that we have recently observed in
simple
molecules and transition metals at pressures of 100 GPa.
Thursday, May 27,
2004
4:10 p.m., 416 Phy/Geo